1,721,119 research outputs found
A measurement study of short-time cell outages in mobile cellular networks
No full textWe study the Short-Time Cell Outages (STCO) phenomena affecting Base Stations (BSs) in a mobile cellular operator network. The STCO is defined as a short-time outage of all or some BS cells (sectors) that lasts up to 30 min in a day, thus still guaranteeing more than 98% of operation. It is type of outage which cannot be detected directly through an operator network monitoring system. Although a complete characterization of STCOs has never been reported in the literature, such events are affecting the cellular network of every mobile operator. In particular, a statistical analysis of STCOs based on BSs measurements of a complete operator mobile network is performed. Our results show that: (i) STCOs impact everyday life of an operator network, (ii) high load of cells corresponds to an increase in the number of STCOs and their duration, (iii) the impact of STCOs to single sectors and whole BSs is not negligible, (iv) most of STCOs are recorded in urban areas compared to rural ones, (v) the impact of STCOs on users is higher in rural areas compared to urban ones, and (vi) the STCOs are correlated with the transferred traffic rather than the outside air temperature
Optimal Energy Management of UAV-Based Cellular Networks Powered by Solar Panels and Batteries: Formulation and Solutions
Full text linkWe focus on the problem of managing the energy consumption of a cellular network tailored to cover rural and low-income areas. The considered architecture exploits Unmanned Aerial Vehicles (UAVs) to ensure wireless coverage, as well as Solar Panels (SPs) and batteries installed in a set of ground sites, which provide the energy required to recharge the UAVs. We then target the maximization of the energy stored in the UAVs and in the ground sites, by ensuring the coverage of the territory through the scheduling of the UAV missions over space and time. After providing the problem formulation, we face its complexity, by proposing a decomposition-based approach and by designing a brand-new genetic algorithm. Results, obtained over a set of representative case studies, reveal that there exists a trade-off between the UAVs battery level, the ground sites battery level and the level of coverage. In addition, both the decomposed version and the genetic algorithm perform sufficiently close to the integrated model, with a strong improvement in the computation times
Energy-Aware Networks: Reducing Power Consumption By Switching Off Network Elements (invited paper)
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PoliSave: Efficient Power Management of Campus PCs
Full text linkIn this paper we study the power consumption of networked devices in a large Campus network, focusing mainly on PC usage. We first define a methodology to monitor host power state, which we then apply to our Campus network. Results show that typically people refrain from turning off their PC during non-working hours so that more than 1500 PCs are always powered on, causing a large energy waste. We then design PoliSave, a simple web-based architecture which allows users to schedule power state of their PCs, avoiding the frustration of wasting long power-down and bootstrap times of today PCs. By exploiting already available technologies like Wake-On-Lan, Hibernation and Web services, PoliSave reduces the average PC uptime from 15.9h to 9.7h during working days, generating an energy saving of 0.6kW/h per PC per day, or a saving of more than 250,000 Euros per year considering our Campus Universit
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